20l hybrid vessel

[SpudFarm]

hello i am looking to make a new hybrid when the first is finished. it is going to be a hell of a monster 20l combustion chamber but i cant find what i am going to use. i was thinking to buy a 20l gas bottle used for methane or something rated to 315 bars (4568psi) so do someone know where to get a 20l gassbottle witch i can buy and not borrow? has to be empty

[POLAND_SPUD]

hmmmm..... this sounds dangerous..... really dangerous...... you really know what you are doing ?

[SpudFarm]

that shouldn't be so more dangerous than a little one. and it should take that pressure easily i am NOT ever going higher than 4x withc is a really little deal for a bottle like that. just think of it 4568psi in all conditions mabe they bail. they should take it in my opinion but if i am a jackass for just thinking of it TELL ME!

[ALIHISGREAT]

hmm well getting a spark and fuel injection kmight be awkward if you use one of those bottles... maybe you could drill and thread the wall?

[thespeedycicada]

dont make it if you wont go over 4x it wouldn't be worth it but FEAR was similar to this i think.

[Hotwired]

Gas cylinders are only rented to you but you could try getting a large steel diving cylinder. Not sure if they go above 15L though.

[POLAND_SPUD]

lol sorry I just thought that you are one of those guys --> " I want to build an uber powerful gun powered by plutonium... help plizz"...

why do you need a 20 l bottle? and what size of barrel are you going to use...? 20 L chamber seems rather big.... I've seen some hybrides here and their chamber are relatively small so I assume that it is going to have rather large bore am I right ?

[cwazy1]

dude, you can buy huge cylinders on craigslist. thers a guy over selling a 100# co2 tank for 50$ each and he has 12 =/

[Novacastrian]

What Poland said, what size barrel do you plan on using 100mm? I have to tell you that this seems like a very large Hybrid. The noise will be similar to an atomic bomb.
In my opinion it is overkill, but if it can be done safely more power to you!
Even with a 100mm barrel it will have to be like 6 metres long. There is no way i would stand next to it whilst firing either so make sure you have a suitable remote ignition devices sorted.
Maybe you could use more than one barrel?

[SpudFarm]

thanks guys!!
i think of a huge 3" barrel and try to make a safety thing on the chamber like a uber burst disk on the side or something but i dosent think so it is a really strong chamber for a 4x so ballvalves and barrels will burst first mabe connect the barrel from the union with a pvc copulig so it is a safety of some sort. and that barrel on a hybrid NEED to have a good shock absorber (thinking of use 3 snowmobile shocks since my father are a proffesional snowmobile modder" then he got a friend witch drives an earth digger and place the cannon in a big hole.

and co2 cylinders are not near the safety i need i am the biggest safety freak on the planet. mabe i can shoot cabbage heads(?)

but it will be a loong time protject with some money this week and some another so its going to take a shit load of time

and just empty your system of comments on me i like to get help by members on this forum bechause this is going to be scary


thanks

[DYI]

I do hope that your skills in written English aren't reflective of your overall brain power... because that would be downright scary.

A bit of searching should uncover some old compressed gas cylinders that have been retired, but you can't buy ones of that size new, in general. Using a retired cylinder carries its own obvious risks however. Killjoy's FEAR was constructed with some 6" SCH 40 welded steel pipe he found lying around in his yard, but a similar length of pipe purchased new would cost several hundred dollars. 20 liters is a LOT of volume. That's ~1220 ci of volume. Even with a 3" barrel, for a proper ratio @4x it would need to be ~72' long. With a 4" barrel, it would still need to be about 40 feet long.

I assume you already have metering and ignition, as well as valving sorted, and would strongly encourage you to figure them out yourself if you don't.

If I were the first response, I wouldn't have answered for the simple fact that if you're planning on building something like this, you should be able to figure it out yourself. Fortunately (or perhaps unfortunately) for you, this is a very forgiving community. Build a smaller hybrid first to get a hold on the principles involved before dumping numerous hundreds on something of such a massive scale.

[SpudFarm]

i use the meter from my SMALLER hybrid just add bigger pipe to it and if i use that it also got air filling. you don't really know the diffrence in living in a large country and a little one like norway (plus i live on the country side) you can get absolutely NOTHING here. i asks to get the design better before i make it!

i know it is really big but then it is even funnier to se and hear the damage and a big massive boom

and i have searched soo long to find a bottle like that it seems that its not possible to get one.
everyone tells me the same thing but i cant get the stuff like you do and it cost allot to ship something that big to me.

dont undarstand me wrong!

[DYI]

It's good to know that English isn't your first language. And I live in the countryside too, in a manner of speaking... Getting parts is a b*tch around here. If you already have a working hybrid, then it shouldn't be a huge problem to simply scale it up.

[zephir]

It sounds like your building a howitzer. Or a large field gun.

If you could, use a really big barrel- like 5" (125mm) or 6" (150mm).

Get a steel (or similar metal) pipe and just weld everything on a frame of some sort. That way you won't need quite as long a barrel and you'll get to shoot much larger things with much more power. If you're really living in the country side (as in far from other people) you shouldn't have too much of a problem with noise or large projectiles hitting people or property.
Mounting everything on a frame would keep everything together (so weight isn't an issue) and mobile.

Some scrapyards have really big metal pipes.

And for ammo, you could use mouse balls as shot and large glass bottles filled with dirt or water for sabot.

[Killjoy]

Killjoy's FEAR was constructed with some 6" SCH 40 welded steel pipe he found lying around in his yard

Actually the pipe was found at a salvage yard for 20 bucks, as was most of the other parts (solenoid valves, guages, etc)

Sounds like one hell of a project you're looking at. One nice thing about having a large chamber is that when you are fueling, there is a lot more forgivness for mistakes. The downside though is that for it to be efficient it would require a massive barrel.
When I built mine I was prepared for the amout of work involved, but it still is somewhat of a pain to move FEAR around because of its size, so I rarely use it.

Personnally, I would say try to go with a smaller hybrid at first, and then work your self up to a bigger one. And trust me, with a smaller hybrid you'll get out more and use it because it will be a lot less work to set up.

But what ever you decide, good luck.